DALLAS (AP) — Southwest Airlines is starting to charge some customers to be able to board aircraft sooner.

The Dallas-based discount carrier said Wednesday that for an extra $10 each way Southwest passengers can automatically reserve a boarding position prior to general check-in. That would allow those customers to begin boarding the plane after certain elite fliers, who don't have to pay add-on fees for early boarding privileges.

Unlike other carriers, Southwest does not offer assigned seating.

The new offering, which can be purchased up to 25 hours prior to the scheduled departure time of the customer's flight, was available for purchase starting Wednesday for travel beginning Thursday.